Prostheses, such as stents, grafts, and the like, are placed within the body to improve the function of a body lumen. For example, stents with substantial elasticity can be used to exert a radial force on a constricted portion of a lumen wall to open the lumen to near normal size.
These stents can be delivered into the lumen using a system which includes a catheter, with the stent supported near its distal end, and a sheath, positioned coaxially about the catheter and over the stent, to prevent abrasion between the stent and body wall as the catheter is directed through torturous body pathways. The catheter may have an enlarged tip adjacent the distal end of the stent that also helps to atraumatically advance the system and protects the stent.
Once the stent is located at the constricted portion of the lumen, the sheath is removed to expose the stent, which is expanded so it contacts the lumen wall. The catheter is subsequently removed from the body by pulling it in the proximal direction, through the larger lumen diameter created by the expanded prosthesis, which is left in the body.